This paper examines the problems of defining and measuring access for blind travelers in an urban transit environment.  Current accessibility measures do little to account for individual differences or the barriers faced by people with restricted mobility.   Independent access to transit and activities in the urban environment are often denied or restricted for those with vision impairments.   Their freedom of movement is not blocked by physical obstacles, but by information, signs, and spatial knowledge that are hard to access without vision.  In this sense, services and facilities are considered inaccessible if people with limited or no vision lack the information necessary to adequately use them.

Thirty legally blind people made five simulated transfers to different transit modes at a transportation terminal to identify specific barriers to successful travel.   Regular blind mobility methods were tested against a Remote Infrared Audible Signage (RIAS) condition to determine if the devices offered a suitable replacement for typical visual cues and information needed for efficient travel and use of transit.  The difficulties of accessing various transit locations and performing necessary tasks were measured, in both conditions, and the extra time penalties were compared and modeled showing the travel constraints of vision loss and the efficacy of using RIAS to increase access.   RIAS provided superior travel times, increased independence, and decreased error production.  

A survey examined differences reported by blind travelers before and after exposure to RIAS.   Many wayfinding tasks faced by transit users were shown to be quite difficult with normal navigation skills and aids, but presented little or no difficulty when using RIAS.  High resistance to make mode transfers, especially in new environments, was reported.  Inaccessible transit caused “non-trips” and also reduced travel and activity participation.   RIAS revealed a hidden demand to travel more often, with greater safety, independence, and efficiency.   These additional audible cues were perceived as enabling the users to access many more types of activities, such as education, employment, recreational, and entertainment.  High monetary benefits were placed on the ability to travel independently and to gain access to urban opportunities, including increased income from employment.